1. Field of the Invention
This invention relates to the arts of remote viewing systems and remote image processing, for purposes such as remote quality inspection, medical procedures, and the like.
2. Background of the Invention
Remote viewing of camera images is well known in the art, from the proprietary arrangements used in systems such as building surveillance, to the more modern “web cams” which are viewable over publicly-accessible computer networks, such as the Internet.
In any remote viewing arrangement, several fundamental components exist, including one or more cameras or imaging devices, a transmission network, and a viewing console. In older arrangements, such as a remote security monitoring configuration, an “analog” camera may be employed which transmits analog video signals (e.g. NTSC or RGB) over a transmission network to a monitoring display (e.g. television or CRT video monitor). In the more advanced versions of these older systems, the camera may be mounted to a motorized gimbal, which allows the camera to be pointed in a variety of positions within 2 or 3 axes. In some systems, the operator at the monitoring display may be able to command the gimbal to point the camera in a desired direction, and in other systems, the gimbal may simply cycle from one axis extreme to another (e.g. auto-panning from left to right).
To provide similar functionality, “web cams” have be developed with the same types of features, although their means of accomplishing these features can be quite different from the older “analog” versions. Web cams have been provided with fixed positions for many applications, including remote security monitoring and public relations promotions (e.g. web cams showing live pictures of ski slopes or beaches). These arrangements including a digital camera with a web server, interconnected to a client computer via a computer network such as a wide area network (“WAN”), local area network (“LAN”), wireless digital network, or the Internet. The client computer may be equipped with proprietary software for receiving and displaying images, or as in many case, may be equipped with “standard” software such as a web browser. The camera “web server” provides digital images in a format compatible with corresponding client computer, such as Joint Photographic Experts Group (“JPEG”) or Graphic Interchange Format (“GIF”) web photos. In more advanced web cam arrangements which provide for moving video transmission to the client computer, proprietary digital video formats may be employed, or standard video data formats (e.g. streaming video) such as the well-known Audio Video Interleave (*.AVI) format. The digital images are sent from the server computer to the client computer using proprietary digital transmission protocols, or standard digital transmission protocols such as Transmission Control Protocol/Internet Protocol (“TCP/IP).
For some advanced uses of web cams, web cams have also been attached to motorized gimbals with remote control from the corresponding client computer. This allows the user the same advantages of the older “analog” systems, in which the client computer establishes a “back channel” or “control channel” through the computer network to the server computer through which gimbal commands may be passed. In such a system, a user may use a gaming joystick on his or her personal computer (“PC”), mouse commands, or on-screen pan controls to send gimbal pointing commands to the remote web cam server computer. When these commands are received by the web cam server computer, the server computer then implements them as control signals to the motors of the gimbal to effect a change in pointing angle of the web cam. Such remotely-controlled web cams are found in more advanced security applications, as well as in some applications such as remote quality inspection, “telemedicine”, and the like.
In most basic applications, the web cams provided are of fairly low-resolution performance, and often transmit only black and white images, in order to minimize the digital transmission bandwidth consumed by the images while in transit from the remote server to the client computer. This allows the images to be provided to the user as quickly as possible with minimized noticeable delays.
For more advanced applications such as telemedicine, the web cams have very high resolution, however. In these cases, the delay of receiving a new image from a recently repositioned web camera may be quite noticeable, which reduces the number of possible applications for such a system to only include non-realtime applications.
Further compounding this problem and trade-off between resolution and image update latency is the fact that for many of these advanced applications, stereoscopic remote monitoring may be required. For example, in order to enable remote surgical procedures, a system with two remote web cams may be employed to provide the surgeon with needed depth perception. In these stereoscopic applications, the bandwidth demand is doubled due to the doubling of the number of cameras. Additionally, use of manual controls such as joysticks and on-screen icons may not be sufficient for the intended application.
As such, there is a need in the art for a remote stereoscopic viewing system which reduces server-to-client image latency and which provides sufficient clarity and resolution for more advanced applications such as telemedicine. Ideally, this new system and method would be compatible with common place technologies, such as the Internet, web browsers, and web servers, in order to maximize the usefulness of the invention. This new system and method should use minimal transmission bandwidth, as well, in order to enable a wider variety of client devices interconnected via lower-bandwidth transmission networks.